Custom bitmap comparer development

Relevant for: GUI tests and components

To develop a custom comparer, you create a COM object that implements the UFT bitmap checkpoint comparer interfaces to perform the following:

  • Accept input from UFT and perform the bitmap comparison.

  • Provide comparison results to UFT.

  • (Optionally) Provide information that UFT can display in the advanced settings in the Bitmap Checkpoint Properties dialog box when a user creates or edits a bitmap checkpoint.

Custom comparers run within the UFT context. You must therefore exercise care when developing your custom comparer, as its behavior and performance will affect the behavior and performance of UFT.

For UFT to recognize the custom comparer, it must be registered to the component category that UFT defines for bitmap comparers. Depending on how you implement your custom comparer, you can design the comparer to register itself when it is installed, or you can provide an additional program that needs to be run at the time of installation. For details, see Install your custom comparer and register it to UFT.

Perform the tutorial in Develop a custom comparer - Tutorial to learn how to create and use a custom comparer. You can then create your own custom comparers in much the same way. For task details, see Develop a custom comparer.

In addition to the tutorial, UFT provides source files that implement a sample custom comparer in different languages. The source files are provided in C++ and in Visual Basic. Both projects generate a similar custom comparer.

You can study the samples to help you learn about developing custom comparers for UFT bitmap checkpoints, or use them as a reference or template when you develop your own custom comparers. For details, see Use the bitmap checkpoint custom comparer samples.